The core problem and solution of CB design (I)

For (PCB) design of printed circuit board is to produce circuit board at the lowest cost by designing principle drawing and circuit layout. In the past, this was usually done with expensive specialized tools, but now, with the popularity of free high-performance software tools and design models, This greatly speeds up the design of circuit board designers.

Although engineers know that a perfect design is the best way to avoid problems, it is still a waste of time and money. At the same time, the treatment of the symptoms is not the cure of the root cause. For example, if a problem is discovered during the (EMC) test phase of EMC, it will result in a lot of cost, and even the original design will need to be adjusted and remade. This will take months.

Layout is one of the first problems designers have to face. This problem depends on the part of the drawing, and some devices need to be set together based on logical considerations. It should be noted, however, that temperature-sensitive components, such as sensors, should be set separately from those that generate heat, including power converters. For designs with multiple power settings, 12-volt and 15-volt power converters can be set in different locations on the circuit board. Because the heat and electronic noise they produce will have an impact on the reliability and performance of other components as well as on the circuit board.

These components will also have an impact on the electromagnetic performance of the circuit design, This is important not only for the performance and energy consumption of the circuit board, but also for the economy of the circuit board. Therefore, all PCB equipment sold in Europe must obtain the CE logo to prove that it will not interfere with other systems. However, this is usually only from the power supply side, and there are many devices that emit noise, such as DC-DC converters, high-speed data converters, and so on. Because of the defects in the circuit board design, the noise can be captured by the channel and radiated as a small antenna.

The problem of far-field electromagnetic interference (EMI) can be solved by installing filters at noise points or shielding signals by metal shell. However, due attention has been paid to the devices on the circuit board that can release electromagnetic interference (EMI), so that the circuit board can choose a cheaper shell, thus effectively reducing the cost of the whole system.

In the design process of the circuit board, Electromagnetic interference (EMI) is a very important factor. Electromagnetic crosstalk can be coupled with the channel, which disrupts the signal to noise and affects the overall performance of the circuit board. If the coupling noise is too high, the signal may be completely covered, so a more expensive signal amplifier must be installed in order to return to normal. However, these problems can be avoided if the layout of signal lines can be fully taken into account at the beginning of circuit board design. Because the design of the circuit board will be different according to different equipment, different places of use, different heat dissipation requirements, and different electromagnetic interference (EMI), then the design template will be used.